4 files changed, 82 insertions, 1 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 8c7e2b7..d23027a 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -847,6 +847,14 @@ zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
 	/* mark unit unusable as long as sysfs registration is not complete */
 	atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 
+	spin_lock_init(&unit->latencies.lock);
+	unit->latencies.write.channel.min = 0xFFFFFFFF;
+	unit->latencies.write.fabric.min = 0xFFFFFFFF;
+	unit->latencies.read.channel.min = 0xFFFFFFFF;
+	unit->latencies.read.fabric.min = 0xFFFFFFFF;
+	unit->latencies.cmd.channel.min = 0xFFFFFFFF;
+	unit->latencies.cmd.fabric.min = 0xFFFFFFFF;
+
 	if (device_register(&unit->sysfs_device)) {
 		kfree(unit);
 		return NULL;
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index bda8c77..306fcd0 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -708,6 +708,24 @@ struct zfcp_erp_action {
 	struct timer_list timer;
 };
 
+struct fsf_latency_record {
+	u32 min;
+	u32 max;
+	u64 sum;
+};
+
+struct latency_cont {
+	struct fsf_latency_record channel;
+	struct fsf_latency_record fabric;
+	u64 counter;
+};
+
+struct zfcp_latencies {
+	struct latency_cont read;
+	struct latency_cont write;
+	struct latency_cont cmd;
+	spinlock_t lock;
+};
 
 struct zfcp_adapter {
 	struct list_head	list;              /* list of adapters */
@@ -723,6 +741,7 @@ struct zfcp_adapter {
 	u32			adapter_features;  /* FCP channel features */
 	u32			connection_features; /* host connection features */
         u32			hardware_version;  /* of FCP channel */
+	u16			timer_ticks;       /* time int for a tick */
 	struct Scsi_Host	*scsi_host;	   /* Pointer to mid-layer */
 	struct list_head	port_list_head;	   /* remote port list */
 	struct list_head        port_remove_lh;    /* head of ports to be
@@ -822,6 +841,7 @@ struct zfcp_unit {
         struct scsi_device     *device;        /* scsi device struct pointer */
 	struct zfcp_erp_action erp_action;     /* pending error recovery */
         atomic_t               erp_counter;
+	struct zfcp_latencies	latencies;
 };
 
 /* FSF request */
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index b2ea4ea..1e71364 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -2005,6 +2005,7 @@ zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *fsf_req, int xchg_ok)
 		fc_host_supported_classes(shost) =
 				FC_COS_CLASS2 | FC_COS_CLASS3;
 		adapter->hydra_version = bottom->adapter_type;
+		adapter->timer_ticks = bottom->timer_interval;
 		if (fc_host_permanent_port_name(shost) == -1)
 			fc_host_permanent_port_name(shost) =
 				fc_host_port_name(shost);
@@ -3649,6 +3650,46 @@ zfcp_fsf_send_fcp_command_task_management(struct zfcp_adapter *adapter,
 	return fsf_req;
 }
 
+static void zfcp_fsf_update_lat(struct fsf_latency_record *lat_rec, u32 lat)
+{
+	lat_rec->sum += lat;
+	if (lat_rec->min > lat)
+		lat_rec->min = lat;
+	if (lat_rec->max < lat)
+		lat_rec->max = lat;
+}
+
+static void zfcp_fsf_req_latency(struct zfcp_fsf_req *fsf_req)
+{
+	struct fsf_qual_latency_info *lat_inf;
+	struct latency_cont *lat;
+	struct zfcp_unit *unit;
+	unsigned long flags;
+
+	lat_inf = &fsf_req->qtcb->prefix.prot_status_qual.latency_info;
+	unit = fsf_req->unit;
+
+	switch (fsf_req->qtcb->bottom.io.data_direction) {
+	case FSF_DATADIR_READ:
+		lat = &unit->latencies.read;
+		break;
+	case FSF_DATADIR_WRITE:
+		lat = &unit->latencies.write;
+		break;
+	case FSF_DATADIR_CMND:
+		lat = &unit->latencies.cmd;
+		break;
+	default:
+		return;
+	}
+
+	spin_lock_irqsave(&unit->latencies.lock, flags);
+	zfcp_fsf_update_lat(&lat->channel, lat_inf->channel_lat);
+	zfcp_fsf_update_lat(&lat->fabric, lat_inf->fabric_lat);
+	lat->counter++;
+	spin_unlock_irqrestore(&unit->latencies.lock, flags);
+}
+
 /*
  * function:    zfcp_fsf_send_fcp_command_handler
  *
@@ -3922,6 +3963,9 @@ zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *fsf_req)
 			      fcp_rsp_iu->fcp_sns_len);
 	}
 
+	if (fsf_req->adapter->adapter_features & FSF_FEATURE_MEASUREMENT_DATA)
+		zfcp_fsf_req_latency(fsf_req);
+
 	/* check FCP_RSP_INFO */
 	if (unlikely(fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)) {
 		ZFCP_LOG_DEBUG("rsp_len is valid\n");
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 099970b..8b1a7d9 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -323,11 +323,18 @@ struct fsf_link_down_info {
 	u8 vendor_specific_code;
 } __attribute__ ((packed));
 
+struct fsf_qual_latency_info {
+	u32 channel_lat;
+	u32 fabric_lat;
+	u8 res1[8];
+} __attribute__ ((packed));
+
 union fsf_prot_status_qual {
 	u64 doubleword[FSF_PROT_STATUS_QUAL_SIZE / sizeof(u64)];
 	struct fsf_qual_version_error   version_error;
 	struct fsf_qual_sequence_error  sequence_error;
 	struct fsf_link_down_info link_down_info;
+	struct fsf_qual_latency_info latency_info;
 } __attribute__ ((packed));
 
 struct fsf_qtcb_prefix {
@@ -437,7 +444,9 @@ struct fsf_qtcb_bottom_config {
 	u32 fc_link_speed;
 	u32 adapter_type;
 	u32 peer_d_id;
-	u8 res2[12];
+	u8 res1[2];
+	u16 timer_interval;
+	u8 res2[8];
 	u32 s_id;
 	struct fsf_nport_serv_param nport_serv_param;
 	u8 reserved_nport_serv_param[16];